Python Docstrings for main classes/functions

[AnHeuermann]

Description

I'm currently in the process of updating a few of the OpenModelica scripts like https://github.com/OpenModelica/OpenModelicaLibraryTesting to OMPython v4 and noticed that a lot of the newish functions/classes aren't documented which makes the upgrade process harder than needed.

Please provide documentation for the main classes and functions like for example OMCSessionZMQ and OMCProcessDocker.

Expected Behavior

Have Python Docstrings for the main classes and functions.

[syntron]

@AnHeuermann I will update the docstrings based on the work on issue #374; if you have any detailed question, feel free to ask

If you plan to create documentation, perhaps use the possible version 4.1.0 with all changes I have (see https://github.com/syntron/OMPython/tree/v4.1.0-test)